i have a 2005 electraglide classic completely stock. when riding the bike between 2000 and 3000 rpm in 1,2,3 gear the bike makes popping sounds and feels like it misses. if you roll on the throttle it runs great until you try to keep it at a steady 25-30 mph. runs good at highway speeds no popping. seems even on slight deceleration it does this. any ideas as to what it could be .Thx